JP3104565B2 - Clutch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch device, and more particularly to a clutch device used in an automatic transmission.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 6-48806.
And in Japanese Patent Application No. 6-69632, a cam mechanism is provided between members that rotate relatively in the circumferential direction, and the cam mechanism converts a circumferential force generated by the relative rotation between the members into an axial thrust, An application for a clutch device using this as a clutch engagement force has been filed. The above-mentioned device makes it possible to reduce the number of clutch disks by utilizing the boosting function and the unidirectionality of the cam mechanism, and to reduce the size of the entire clutch device by eliminating the one-way clutch. And
When the cam angle is θ and the friction coefficient between the clutch disk and the cam member pressing the clutch disk is μ, μ> tan θ
It is noted that a self-locking action in which the engaging force increases in accordance with the rotational torque is obtained at the time of, and a boosting action in which the engaging force increases in accordance with the pressing force of the piston pressing the cam mechanism when μ <tanθ is obtained. The cam surface is bidirectional, one cam surface is for obtaining a self-locking effect, and the other cam surface is for obtaining a boosting effect, that is, a self-locking cam and a booster cam are provided. It has been proposed to obtain a self-locking action when the direction of relative rotation of a relatively rotating member is in a certain direction, and to obtain a boosting action in a reverse rotation direction.

[0003]

By the way, in the above-mentioned clutch device, when the clutch device is released in the reverse rotation direction, the clutch disk and the cam member for pressing the clutch disk must be separated from each other so that the clutch disk is not required due to the action of the booster cam. Thrust is generated and drag loss increases. For this reason, a return spring is provided to apply an urging force for separating the two members. However, the thrust of the self-locking cam is reduced by the urging force of the return spring, and as a result, the self-locking cam is transmitted from the engaged state in the normal rotation direction. When the torque is released, the clutch device slips before the direction of the transmission torque reverses, and there is a problem that the driving feeling is deteriorated such that the engine load suddenly decreases and the engine blows up.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a clutch device capable of securely engaging with a self-locking engagement when a pair of members that rotate relative to each other rotate in a certain direction, and reliably rotating when rotating in the opposite direction. The purpose is to provide.

[0005]

According to the first aspect of the present invention, a pair of members which are spaced apart from each other on a common axis and are relatively rotated, a first frictional engagement element and a second frictional engagement which can be engaged with each other. A first frictional engagement element that is engaged with one of the pair of members and is restricted from moving in the axial direction toward the second frictional engagement element; and a first element that is engaged with the other of the pair of members. A clutch device comprising a first frictional engagement element and a second frictional engagement element arranged adjacent to each other, wherein the first and second frictional engagement elements are frictionally engaged to engage a pair of relatively rotating members. A cam mechanism comprising a first cam mechanism and a second cam mechanism disposed between a pair of members on a common axis, wherein the first cam mechanism has cam surfaces facing each other, and First and second cam members movable in a direction, wherein a back surface opposite to the cam surface has a rear surface opposite to the cam surface. A first cam member which surface is opposition to one of the first member, the rear surface of the opposite side of the cam surface,
A second cam member directly or indirectly brought into contact with the second frictional engagement element, wherein the second cam mechanism has first and second axially movable first and second axially movable cam surfaces. A first cam member having a rear surface opposite to the cam surface directly or indirectly abutting against one of the first members; and a second friction engagement element having a rear surface opposite to the cam surface. And a second cam member of the first cam mechanism, which includes a second cam member opposed to the second cam member, and presses the second cam member of the first cam mechanism toward the side opposite to the first cam member. A pressing means for pressing the cam member toward the second frictional engagement element; and an urging means for applying an axial urging force to a part of the cam mechanism, wherein the second frictional engagement element and the first engagement element engaged therewith are provided. The friction coefficient between the cam mechanism and the back surface of the cam member is represented by μ,
The inclination angle of the cam mechanism with respect to the plane perpendicular to the axis of the cam surface is β,
When the inclination angle of the cam surface of the second cam mechanism with respect to the plane perpendicular to the axis is α, the inclination angle β of the cam surface of the first cam mechanism is ta.
nβ> μ, the second cam mechanism has a cam surface inclined to the side opposite to the inclination angle of the first cam surface, the inclination angle α is tanα <μ, and the second frictional engagement element is coupled. If the second cam member of the second cam mechanism is pressed against the second friction engagement element by the piston means while the other of the pair of members is rotating, the first cam mechanism does not operate, and the second cam The back surface of the second cam member of the mechanism is frictionally engaged with the second frictional engagement element and dragged by the second frictional engagement element, and the pair of opposed cam members of the second cam mechanism rotate relative to each other and separate from each other. Direction, the first cam member of the second cam mechanism abuts directly or indirectly on one of the pair of members, and the first friction engagement element is pressed against the second friction engagement element by the second cam member. The movement in the axial direction is restricted, and the second friction engagement element and the first friction engagement element Frictional engagement with the corresponding pressing force,
After the frictional engagement, when the other rotation direction of the pair of members to which the second frictional engagement element is coupled is reversed, the separation between the first cam member and the second cam member of the second cam mechanism is eliminated, and The second cam member of the cam mechanism is directly or indirectly dragged by the other of the pair of members, and the pair of opposing cam members of the first cam mechanism are relatively rotated and pressed in directions away from each other.
The second frictional engagement element is pressed against the first frictional engagement element directly or indirectly by the back surface of the second cam member of the cam mechanism to form the second frictional engagement element.
The friction engagement element and the first friction engagement element are frictionally engaged with a force corresponding to the pressing force of the pressing means, and the urging means presses the second cam member of the first cam mechanism toward the first cam member. Provided is a clutch device that provides an urging force.

According to the second aspect, in the first aspect, when the other of the pair of members is rotating so that the second cam mechanism operates, the pressing means cancels the urging force of the urging means. And a clutch device is provided.

According to a third aspect, in the first aspect, the urging force of the urging means when the other of the pair of members is rotating so that the first cam mechanism operates is operated by the second cam mechanism. The clutch device is characterized in that the biasing force is smaller than the biasing force of the biasing means when the other of the pair of members is rotating.

According to a fourth aspect, in the third aspect, the urging means is provided between the spring member and the first cam member of the first cam mechanism to support the spring member. And when the other of the pair of members is rotating so that the first cam mechanism operates, the support member receives the spring force of the spring member so as not to apply an urging force. Is provided.

According to a fifth aspect, in the third aspect, the biasing means is constituted by a spring member whose posture is changed by the relative rotation of the cam member, and the other of the pair of members is operated so that the first cam mechanism operates. There is provided a clutch device characterized in that a spring member is made to have a natural length during rotation so as not to apply an urging force.

According to a sixth aspect, in the third aspect, the biasing means is constituted by a spring member whose posture is changed by the relative rotation of the cam member, and the other of the pair of members is operated so that the first cam mechanism operates. The amount of contraction of the spring member during rotation is
The second cam mechanism is operated so that the other of the pair of members is smaller than the contraction amount when the other is rotating,
The urging force of the urging means when the other of the pair of members is rotating so that the first cam mechanism operates is used when the other of the pair of members is rotating so that the second cam mechanism operates. A clutch device is provided which is smaller than the urging force of the urging means.

[0011]

According to the first aspect, when the first cam member and the second cam member of the first cam mechanism are separated from each other and the pair of members are engaged with a force corresponding to the pressing force of the pressing means, the urging is performed. Since the means acts in a direction in which the first cam member and the second cam member of the first cam mechanism approach each other, the engagement is reliably released when the pressing force is released.

In the second aspect, when the first cam member and the second cam member of the second cam mechanism are separated from each other and the pair of members are engaged, the pressing means cancels the urging force. I can't be weakened. On the other hand, when the first cam member and the second cam member of the first cam mechanism are separated from each other and the pair of members are engaged with a force corresponding to the pressing force of the pressing means, the urging means is in the first position.
Since the first and second cam members of the cam mechanism act in a direction of approaching each other, when the pressing force is released, the engagement is reliably released.

According to a third aspect of the present invention, when the first cam member and the second cam member of the second cam mechanism are separated from each other and the pair of members are engaged, the urging force is eliminated or reduced. If so, they can be weakened at all or only a little. On the other hand, when the first cam member and the second cam member of the first cam mechanism are separated from each other and the pair of members are engaged with a force corresponding to the pressing force of the pressing means, the urging means is the first cam mechanism. Acts in a direction to bring the first and second cam members closer to each other, so that when the pressing force is released, the engagement is surely released.

According to a fourth aspect of the present invention, when the first cam member and the second cam member of the second cam mechanism are separated from each other and the pair of members are engaged, that is, the other of the pair of members rotates as described above. The spring force of the biasing means is received by the support member,
Since it does not act on the second cam mechanism, the engagement is not weakened. On the other hand, when the first cam member and the second cam member of the first cam mechanism are separated from each other and the pair of members are engaged with a force corresponding to the pressing force of the pressing means, When the rotation of the other side is reversed, the spring force
Since the first and second cam members of the cam mechanism act in a direction of approaching each other, when the pressing force is released, the engagement is reliably released.

In the fifth aspect, when the first cam member and the second cam member of the second cam mechanism are separated from each other and the pair of members are engaged, that is, when the other of the pair of members rotates like this. In this case, the spring of the urging means does not generate a spring force, so that the engagement is not weakened. On the other hand, when the first cam member and the second cam member of the first cam mechanism are separated from each other and the pair of members are engaged with a force corresponding to the pressing force of the pressing means, When the rotation of the other side is reversed, the spring force acts in a direction to bring the first cam member and the second cam member of the first cam mechanism closer to each other.
When the pressing force is released, the engagement is surely released.

In the present invention, when the first cam member and the second cam member of the second cam mechanism are separated from each other and the pair of members are engaged, that is, the other of the pair of members rotates as described above. In this case, since the spring force of the biasing means is small, the engagement is weakened only slightly. On the other hand, when the first cam member and the second cam member of the first cam mechanism are separated from each other and the pair of members are engaged with a force corresponding to the pressing force of the pressing means, When the rotation of the other side is reversed, a large spring force acts in a direction to bring the first cam member and the second cam member of the first cam mechanism closer to each other, so that when the pressing force is released, the engagement is surely released.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, FIG. 1 schematically shows an entire conventional automatic transmission in order to explain to which part of the entire conventional automatic transmission the embodiment of the present invention is applied. . In FIG. 1, AT indicates the entire transmission mechanism of the conventional automatic transmission. The transmission mechanism AT is basically composed of three planetary gear units and their respective elements such as a ring gear, a sun gear, and a carrier. It consists of a friction engagement element that makes contact. The details are as follows. X _i is an input shaft, which is connected to an output shaft (not shown) of a torque converter (not shown). PG ₁ , PG ₂ and PG ₃ are a front planetary gear unit, a rear planetary gear unit,
This is an O / D planetary gear unit.

R ₁ , R ₂ , R ₃ are a front planetary ring gear, a rear planetary ring gear, an O / D
This is a planetary ring gear. K ₁ , K ₂ , and K ₃ are a front planetary carrier, a rear planetary carrier, and an O / D planetary carrier, respectively. S ₁₂ is the front planetary gear unit, a common front and rear planetary sun gear to the rear planetary gear unit, S ₃ is O / D planetary sun gear. C ₁ is a first clutch and disengaging the input shaft X _i and the front planetary ring gear R _1. C ₂ is second
A clutch, for engaging and disengaging the input shaft X _i and the front and rear planetary sun gear S _12. C ₃ is the third
A clutch, O / D planetary carrier K ₃ and O
/ D planetary sun gear S ₃ for engaging and disengaging.

B ₁ is the first brake, which is
To lock the rear planetary sun gear S _12. B ₂ is second
A first one-way clutch F
To lock the reverse rotation of the front and rear planetary sun gear S ₁₂ (left rotation) through the _1. B ₃ is a third brake to lock the rotation of the rear planetary carrier K _2. B ₄ is a fourth brake, which locks the rotation of the O / D planetary sun gear S _3.

F ₁ is a first one-way clutch,
The second brake B ₂ to lock the front and rear planetary reverse rotation of the re-sun gear S ₁₂ (left rotation) when you are working.
F ₂ is a second one-way clutch to lock the reverse rotation of the rear planetary carrier K ₂ (left rotation). F ₃
It is a third one-way clutch to lock the reverse rotation of the O / D planetary carrier K ₃ for O / D planetary sun gear S ₃ (left rotation). Note that CG ₁ is a counter drive gear, and CG ₂ is a counter driven gear for guiding engine output to a subsequent mechanism, and is not related to the shift itself.

In the following embodiments, the functions of the third brake B ₃ and the second one-way clutch F ₂ are performed. Therefore, as shown in FIG.
Range, 2 range, locks the counterclockwise rotation of the rear planetary carrier K ₂ in the drive traveling first speed stage of the L range, L
Locks the clockwise rotation of the rear planetary carrier K ₂ in the driven running (engine brake state) of the first speed stage of the range, also locks the clockwise rotation of the rear planetary carrier K ₂ in driving the travel of R-range, it is necessary to lock the counterclockwise rotation in the driven traveling, also, D-range, 2-range, the first speed stage of the L range at the time of shifting to the second speed stage, the allotted torque of the rear planetary carrier K ₂ direction immediately shifts to the right rotating idly the rear planetary carrier K ₂ simultaneously reversed from left rotation lock state, the second
From the speed stage at the time of shifting to the first speed stage, it is necessary to rear planetary carrier K ₂ is locked rear planetary carrier K ₂ simultaneously with inverted from clockwise to counterclockwise rotation.

FIG. 3 is a sectional view of the automatic transmission in which the first embodiment of the present invention is incorporated. A clutch casing 100 having an annular concave portion for receiving the clutch device 1 of the present invention is provided in a transmission case 200. Integrally formed,
The first cam member 2, the piston 3, and the second cam member 4 are disposed in an annular concave portion of the clutch casing 100. A first cam roller 5 is provided between the first cam member 2 and the piston 3, and a second cam roller 6 is provided between the piston 3 and the second cam member 4. It is biased to the left. In this embodiment, the first cam member 2 is formed separately from the clutch casing 100.
Although it is fixed to 00, it may be formed integrally with the clutch casing 100. Further, the transmission case 200 is provided with an oil passage 200a for supplying hydraulic pressure to the piston 3.

On the other hand, the clutch disc 8 is connected member Ka in mounted axially slidably rotating integrally with the rear planetary carrier K ₂ of the rear planetary gear PG _2,
Also, the separator plate 9 is used for the transmission case 200
Are slidably mounted in the axial direction. Clutch disk 8 and separator plate 9
Is extended in the axial direction and the rightmost separator plate 9
It engaged with each other when pressed against the clutch disc 8 locks the rotation of the rear planetary carrier K ₂ is stopped.

FIG. 4 is a cross-sectional view of the clutch device 1 of FIG. 3 as viewed from the radial direction. A pair of cam surfaces 2L and 3L are provided on a surface where the first cam member 2 and the piston 3 face each other. A pair of cam surfaces 3R and 4R are provided on the surfaces of the piston 3 and the second cam member 4 facing each other. Therefore, the piston 3 has cam surfaces on both end surfaces. The cam angle α of the cam surfaces 3R and 4R and the cam angle β of the cam surfaces 2L and 3L are tan α when the friction coefficient between the second cam member 4 and the clutch disk 8 is μ.
<Μ, tan β> μ. Incidentally, the clutch disk 8 when the clutch device 1 does not act to rotate the rear planetary carrier K ₂ and integrally as described above, are shown so as to move to the left and right in the figure, rotates so as to move to the left The case where the rotation is performed is referred to as forward rotation, and the case where the rotation is performed so as to move rightward in the drawing is referred to as reverse rotation.

FIG. 4 shows a state in which no hydraulic pressure is supplied and the clutch device 1 has the shortest axial length. The clutch disk 8 and the second cam member 4 are separated from each other, and the clutch disk 8 Regardless of forward rotation or reverse rotation, the rotation is not stopped. Next, the clutch disk 8
When the hydraulic pressure is supplied during normal rotation, the gap between the first cam member 2 and the piston 3 increases, and the piston 3 and the second cam member 4 are integrated with the second cam roller 6 interposed therebetween as shown in FIG. Is pressed against the clutch disc 8.

As a result, the second cam member 4 and the clutch disk 8 are frictionally engaged, and the second cam member 4 is also dragged by the clutch disk 8 and starts rotating in the normal rotation direction.
μ, the cam surface 4R of the second cam member 4
Is the cam surface 3 of the piston 3 via the second cam roller 6.
R, a cam thrust is generated, the piston 3 is pushed back downward in the figure, and the gap between the first cam member 2 and the piston 3 that has once expanded is minimized, and the reaction force of the cam thrust is reduced. The first cam member 2 is in a receiving state. As a result, the second cam member 4 and the clutch disc 8 are engaged in a self-locking manner.
This self-locking engagement, hereinafter referred to as self-locking engagement, increases the engaging force as the rotational torque of the clutch disk 8 increases. FIG. 6 shows a state of self-locking engagement in this manner. As a result, it is possible to lock the rear planetary carrier K ₂ when the clutch disk 8 is trying to forward.

On the other hand, when the hydraulic pressure is supplied during the reverse rotation of the clutch disk 8, the second cam member 4 and the clutch disk 8 are frictionally engaged after the state shown in FIG. The disk 3 starts to rotate in the reverse direction by being dragged by the disk 8, and accordingly, the piston 3 also moves to the second cam roller 6.
Starts to rotate in the reverse direction through the cam surface 3 of the piston 3
L goes up the cam surface 2L of the first cam member 2 via the first cam roller 5, and a cam thrust is generated, and the second cam member 4 and the clutch disc 8 are engaged with the clutch disc 8 by the cam thrust. FIG. 7 shows the state of the engagement. As a result, it is possible to lock the rear planetary carrier K ₂ when the clutch disk 8 is trying to reverse. As described below, this engagement boosts the thrust by the hydraulic pressure, and is hereinafter referred to as boost engagement.

The engaging force F of the clutch device 1 at this time is the sum of the cam thrust by the cam and the thrust by the hydraulic pressure, and increases and decreases in proportion to the hydraulic pressure. The thrust by the hydraulic pressure is Fp, and the urging force of the return spring 7 is Fs is expressed by the following equation (1). F = a (Fp−Fs) (1) where a is a constant determined by the magnitude of the cam angle β determined so that tan β> μ. Therefore, the thrust Fp by the hydraulic pressure is applied to the urging force Fs of the return spring 7.
If it is smaller, the engagement force disappears and the engagement is released. As described above, in the first embodiment, the biasing force of the return spring 7 does not act on the second cam member 4 and the self-locking engagement in the normal rotation direction can be ensured. and allowing the biasing force of the spring 7 is carried out without generating a dragging to the reverse rotation direction idling action, in the prior art, B ₃ and F ₂ can be reliably performed role plays.

FIG. 8 shows the structure of a cam portion according to a second embodiment of the present invention. In contrast to the first embodiment, the cam between the first cam member 2 and the piston 3 is replaced by a flat cam 2P, The configuration is 3P, and the other configuration is the same as that of the first embodiment. As a result, the first cam roller 5 becomes unnecessary,
Since the surface pressure of the cam surface is also reduced, it is possible to reduce the axial dimension. Note that the basic operation and effect are the same as those of the first embodiment, so that the description thereof will be omitted.

FIG. 9 is a view showing the structure of a third embodiment of the present invention. As shown in FIG. 9, a cam mechanism for generating an engaging force during normal rotation and a cam for generating an engaging force during reverse rotation. It is provided separately from the mechanism. Therefore, piston 3
A cam surface similar to the cam surface 3L of the first embodiment is disposed on the end surface facing the first cam member 2 of FIG. 3A, but engages with the clutch disk 8 on the end surface facing the clutch disk 8. Only the surface is formed. Then, the second cam member 3b and the third cam member 4 are disposed on the opposite side of the piston 3a with the clutch disk 8 and the separator plate 9 therebetween.
The cam surfaces 3R, 4R of the first embodiment are provided on the facing surfaces of the second cam member 3b and the third cam member 4a, respectively.
Are formed, and the second cam roller 6 is disposed therebetween. When hydraulic pressure is supplied, the piston 3
a moves rightward in the figure and presses the clutch disk 8. However, since the clutch disk 8 and the separator plate 9 are both movable in the axial direction, they do not engage until a cam thrust is generated.

FIG. 10 is a sectional view of the engaging portion viewed from the radial direction, similarly to FIG. 4, but since the clutch disk 8 is engaged with the rear side of the second cam member 3b, the second cam member 3b
And the cam surfaces 3bR and 4aR provided on the third cam member 4a
The cam surfaces 3R and 4R provided on the piston 3 and the second cam member 4 of the first embodiment have the opposite inclination. Although the basic operation and effect are the same as those of the first embodiment, a description thereof will be omitted. However, even when the space between the clutch casing 100 and the clutch disk 8 is so narrow that a cam mechanism cannot be provided, the cam mechanism is provided. There is an advantage that it can be installed.

FIG. 11 is a view showing the structure of the fourth embodiment, in which a hydraulic pressure required to cancel the urging force of the return spring is applied to the piston during self-locking engagement. A shift valve 1 is provided in the middle of an oil passage 300 from a hydraulic pressure source (not shown) to an oil passage 200a of the transmission case 200.
0 is provided, and the hydraulic pressure is supplied to the clutch device 1 by turning on the shift valve 10.
In the fourth embodiment, an oil passage 400 for guiding hydraulic oil to the check valve 11 is provided midway between the shift valve 10 and the oil passage 200a, and a drain control valve 12 is provided in series along the oil passage 400. Has been established. Therefore, the drain control valve 12
When hydraulic oil is supplied from the shift valve 10 in the state of N, the hydraulic pressure adjusted to the set pressure of the check valve 11 is supplied to the clutch device 1 and no more hydraulic pressure is supplied. Reference numeral 13 denotes an orifice for controlling the flow rate of hydraulic oil. The cam mechanism has a structure as shown in FIG. 12, and the opposing surfaces of the first cam member 2a and the piston 3c are respectively similar to the first embodiment for engagement during normal rotation. Cam surfaces 2L and 3L as a two-cam mechanism and cam surfaces 2R and 3R as a first cam mechanism for engagement at the time of reverse rotation are continuously formed.

Here, the set pressure of the check valve 11 is set to a value obtained by dividing the urging force of the return spring 7 when the return spring 7 is contracted until the initial frictional engagement is induced by the pressure receiving area of the piston. Keep it. If the shift valve 10 is turned on and the hydraulic pressure is supplied while the clutch disc 8 is rotating in the normal rotation direction with the above setting, initial frictional engagement is induced, and the first embodiment is performed. Similarly to the above, a cam thrust is generated and self-locking engagement is performed.
At this time, since the urging force of the return spring 7 is canceled, the engagement is reliable. Next, when the clutch disc 8 rotates in the reverse direction while supplying the hydraulic pressure, only the urging force of the return spring 7 is applied with the hydraulic pressure. Therefore, according to the above-mentioned equation (1), the thrust for the engagement is not generated, and the idle rotation is performed. As described above, the fourth embodiment makes it possible to secure the self-locking engagement in the forward rotation direction, and to perform the idling in the reverse rotation direction without causing dragging. B ₃ and F ₂ can be reliably performed role plays.

FIG. 13 shows the structure of a fifth embodiment of the present invention, in which an accumulator 14 is provided instead of the check valve 11 in the fourth embodiment. The accumulator 14 operates to reduce the hydraulic pressure generated by the hydraulic pressure source for a predetermined time. Therefore, while the accumulator 14 is operating, the hydraulic pressure is applied only for the load of the return spring 7. When the accumulator 14 does not act, the outlet pressure of the shift valve 10 acts as it is.

[0035] For example, at the time of shifting from the second speed stage to the first speed stage, it is necessary to rear planetary carrier K ₂ is engaged at the same time the clutch to migrate to the left rotation from clockwise rotation. When the shift valve 10 is turned on, the supply of the hydraulic pressure is started. At this time, only the urging force of the return spring 7 is applied for a predetermined time by the operation of the accumulator 14 set as described above, so that the reverse rotation is performed. Does not occur. Therefore, even if the movement in the reverse rotation direction remains, the engagement in the reverse rotation direction does not occur. Then, while the operation of the accumulator 14 is maintained, the rotation of the clutch disk 8 is switched in the normal rotation direction, so that when the rotation of the clutch disk 8 is switched, as in the first embodiment. A cam force is generated, and self-locking engagement is reliably performed. Therefore,
In the fifth embodiment, the self-locking engagement can be securely performed, and when the rotation is changed from the reverse rotation direction to the normal rotation direction, the operation of locking the rotation in the normal rotation direction can be performed without dragging in the reverse rotation direction. , B ₃ and F ₂ can reliably perform their roles.

Next, a sixth embodiment will be described. In the sixth embodiment, a spring seat is provided between a piston and a return spring, and when the piston rotates relative to the clutch casing, the spring seat rotates. In a self-locking state so that the biasing force of the return spring is not applied to the piston. FIG. 14 is a sectional view showing the structure of the sixth embodiment, and FIG.
It is the figure which looked along the I side. Cam, clutch disc,
Since the separator plates are the same as in the fourth and fifth embodiments, the same numbers are used. The spring seat 15 is disposed between the return spring 7a and the piston 3d. The spring seat 15 has a projection 17 formed on the piston 3d at an outer peripheral end.
And a protrusion 18 provided at an end on the inner peripheral side is fitted to a guide hole 19 provided in the clutch casing 100 to restrict the movement.

FIG. 16 is a sectional view showing the positions of the piston 3d and the spring seat 15 when the hydraulic pressure is not supplied to the piston 3d and the clutch disk 8 is idling in the normal rotation direction. FIG. FIG. 10 is a diagram showing a positional relationship between fifteen projections 18 and guide holes 19 of the clutch casing 100 as viewed from the outside of the clutch casing 100 toward the center.

Next, as shown in FIGS. 18 and 19, the hydraulic pressure is applied from the above state, the piston 3d moves rightward in the figure, the clutch disc 8 and the piston 3d come into contact, and frictional engagement starts. The state immediately before. As shown, the piston 3d and the spring seat 15 are in close contact with each other, while the positional relationship between the projection 18 of the spring seat 15 and the guide hole of the clutch casing 100 is as shown in FIG. Not in a restrained state.

Then, the clutch disk 8 and the piston 3
When the clutch d is frictionally engaged, the piston 3d is dragged by the clutch disc 8 and rotates in the same normal rotation direction as the clutch disc 8, but at this time, the spring seat 15 also
And rotate in the same forward direction. Therefore,
The projection 18 of the spring seat 15 which was in the position shown in FIG. 19 in the previous state moves upward in the figure inside the guide hole 19 of the clutch casing 100, but the guide edge of the guide hole 19 is as shown in the figure. The projection 18 moves to the right in the figure along the upward direction, so that the spring seat 15 is separated from the piston 3d, and the biasing force of the return spring 7a is applied to the piston 3d. The engagement is performed without being affected by the biasing force of the return spring 7a. In addition,
This state is shown in FIGS. On the other hand, when reversely engaging the boosting force, the projection 18 of the spring seat 15 is
Since the guide edge of the guide hole 19 is in contact with the portion extending in the axial direction as indicated by 18 ', the axial position cannot be changed any further, and the piston 3d and the spring seat 15 are in contact with each other. The state is maintained. Therefore, if the hydraulic pressure is released from that state, the piston 3d is pushed to the neutral position, and the piston 3d idles in the reverse direction without dragging. As described above, the sixth embodiment makes it possible to secure the self-locking engagement in the forward rotation direction, and to perform the idling in the reverse rotation direction without causing dragging. B ₃ and F ₂ can be reliably performed role plays.

Next, a seventh embodiment will be described with reference to FIGS. 22 and 23. In the seventh embodiment, the return spring falls down when the piston and the clutch disc are engaged by self-locking. In the self-locking state, the urging force of the return spring 7 is prevented from acting on the piston. In FIG. 22, reference numeral 7b denotes a return spring. The upper end of the return spring 7b in the figure is attached to a spring support plate 20 fixed to a clutch casing 100 (not shown) at right angles to the axis and around the axis. Is rotatably mounted on a spring mounting pin 21 mounted in the radial direction of the circumference of the circle, and a ball 22 is mounted on the opposite end on the piston side. On the other hand, as in the fourth, fifth and sixth embodiments, the piston 3e having the cam surface is provided with the ball 22 of the return spring 7b.
A receiving hole 23 is formed. The return spring 7b is disposed radially inward of the portion where the cam mechanism is disposed.

FIG. 22 shows a state in which the piston 3e and the clutch disc 8 are disengaged, and the ball 22 at the piston-side end of the return spring 7b has the receiving hole 23 of the piston 3e. Has been accepted by
The length of the return spring 7b is shorter than its natural length, and the piston 3e receives the urging force of the return spring 7b.

Next, the piston 3e and the clutch disk 8
Is engaged with the clutch disc 8
And move to the left in the figure. At this time, the piston-side end of the return spring 7b moves leftward in the drawing together with the piston 3e until it is dragged by the receiving hole of the piston 3e. When the distance becomes longer than the natural length of the return spring 7b, the urging force on the piston 3e is eliminated, and the receiving hole is separated from the receiving hole, and a state as shown in FIG. 23 is established. On the other hand, when the clutch disk 8 rotates in the reverse direction and engages with the boosting force, the ball 22 is in the ball receiver 23 and the return spring 7b is shorter than the natural length. Since the force to extend acts, if the hydraulic pressure is released, the piston 3e is pushed to the neutral position, so that the piston 3e runs in the reverse direction without dragging. Therefore, by determining the specifications as described above, the seventh embodiment can
The self-locking engagement in the forward direction can be assured, also make it possible to carry out without generating a drag idling in the reverse direction, in the prior art, the role of B ₃ and F ₂ was responsible Can be performed reliably.

Next, a description will be given of an eighth embodiment. In the eighth embodiment, a return spring is rotatably mounted on both a spring support plate and a piston, and generates a thrust for moving the piston in the self-locking direction at the time of self-locking engagement. In addition, the urging force in the axial direction on the piston is reduced, and a thrust is generated to push the piston back to the neutral position at the time of boosting engagement. FIG. 24 shows the structure of the eighth embodiment. Reference numerals 20 and 21 denote a spring support plate and a spring mounting pin, respectively, as in the seventh embodiment. Reference numeral 24 denotes a spring mounting pin mounted on the piston 3f. Both ends of the return spring 7c are rotatably mounted on spring mounting pins 21 and 24, respectively.

FIG. 25 is a view schematically showing the positional relationship between the spring attachment points at the time of self-locking engagement, at the time of boosting engagement, and at the neutral position. In the figure, pushing the L ₀ is the position of the surface of the piston 3f piston 3f a spring mounting pin 24 is mounted in a neutral state in which returned completely to the first cam member 2a side, L ₁ is the piston 3f the clutch disc 8 This is the position of the surface of the piston 3f where the spring mounting pin 24 is mounted when the piston 3f is engaged.

Point O is the position of the spring mounting pin 21 on the side of the spring support plate 20, and points P ₀ , P ₁ , and P ₂ are the springs in the neutral state, the self-locking engagement state, and the boost engagement state, respectively. shows the location of the mounting pin 24, P ₃ is the position of the spring mounting pin 24 when the return spring 7c is inclined in self-locking engagement side by the cam angle alpha, P ₄ is a return spring 7c only cam angle β booster engagement The virtual position of the spring mounting pin 24 when inclined to the side is shown. θ ₁ and θ ₂ are inclinations of the return spring 7c from the neutral state when the spring mounting pin 24 is at the positions of P ₁ and P ₂ . As shown in the figure, in the neutral state, the surfaces of the return spring 7c and the piston 3f are perpendicular to each other.

[0046] Also, Q₀, Q₁, Q_Two, Q_Three, Q_FourIs
The spring mounting pin 24 is₀, P₁, P_Two,
P_Three, P_FourVirtual return spring 7c
This is a very long point. Here, a cam having a cam surface with a cam angle A 1
When the stone rotates and the spring tilts θ, the spring
The contraction amount ΔS from the natural length S is expressed by the following equation. ΔS = S [1- {1 / (tanA × sin θ + cos θ)}] This equation shows that the maximum value S (1-cos A) when θ = A
FIG. 26 is a graph.

Therefore, when 0 <θ <A, ΔS monotonously increases, and the return spring acts in the direction in which θ decreases, that is, in the direction to return the piston to the neutral position. Conversely, when A <θ, ΔS monotonously decreases, so that the return spring acts in the direction in which θ increases, that is, in the direction to move the piston away from the neutral position. Therefore, as shown in FIG. 25, for example, as the position P ₁ of the spring mounting pin 24 when self-locking engagement, the inclination θ of the return spring 7c is when to be greater than the cam angle alpha, the return spring Since the spring force of 7c acts in the direction of moving the piston 3f in the self-locking direction and ΔS decreases, the self-locking engagement is not weakened by the action of the return spring 7c.

[0048] On the other hand, at the time of the booster engagement, as the position of the spring mounting pin 24 is P _2, the return spring 7
If the inclination θ of c is smaller than the cam angle β,
Since the return spring 7c attempts to return the piston 3f to the neutral position, if the hydraulic pressure is released, the piston 3f is pushed to the neutral position and idles in the reverse direction without dragging. Therefore, by determining the specifications as described above, in the eighth embodiment, the self-locking engagement in the forward rotation direction can be ensured, and the idle rotation in the reverse rotation direction is performed without causing dragging. it possible, in the prior art, B ₃ and F ₂ can be reliably performed role plays.

Next, FIG. 27 shows the structure of the ninth embodiment, which differs from the eighth embodiment in that the return spring 7c is inclined at the neutral position. Figure 28 is a diagram for explaining the way of its setting, as in FIG. 25, P ₅ is the position of the piston 3f side of the spring mounting pin 24 in a neutral state, from the vertical axis of the return spring 7c at that time When the inclination and θ _5, θ ₅ is set so as slightly smaller than α inclination of self locking side of the cam. P ₆ is the position of the spring mounting pin 24 at the time of self-locking engagement, θ ₆ is the inclination at that time, θ ₆ > α, P ₇ is the position of the spring mounting pin 24 at the time of boosting engagement, θ ₇ is It is the inclination at that time and θ ₇ <
β.

The return spring 7c is set in this manner.
When the hydraulic pressure is supplied, the piston 3f moves upward in the figure.
The vertical axis of the return spring 7c
From the cam angle α, and eventually becomes larger than the cam angle α.
You. As described above, is the vertical axis of the return spring 7c
If these inclinations are larger than the cam angle α, ie, P _Five
Line and line segment OQ extending upward from₈Intersection P of₈Above
The spring force of the return spring 7c is fixed
Act 3f in the direction of self-locking.
After that, the piston 3f is disengaged without supplying hydraulic pressure.
Induces frictional engagement by pressing against the disc 8 to generate cam force.
Therefore, self-locking engagement can be performed.

On the other hand, when the boosting is engaged, as in the eighth embodiment, a force for returning to the neutral position acts, and when the hydraulic pressure is released, the return spring 7c returns to the neutral position and drags. Idling in the reverse direction without occurrence of Therefore, by determining the specifications as described above, in the ninth embodiment, the self-locking engagement in the forward rotation direction can be ensured, and the idle rotation in the reverse rotation direction is performed without causing dragging. it possible, in the prior art, B ₃ and F ₂ is able to reliably perform role plays, further, compared with the eighth embodiment, a small hydraulic give to induce the self-locking engagement It has the advantage of being good.

[0052]

According to each aspect of the present invention, when a pair of members relatively rotating by the first cam mechanism are engaged with a force corresponding to the rotational torque, a force for reducing the engaging force does not act. Or small, this engagement can be assured. On the other hand, when the second cam mechanism is engaged with a force corresponding to the pressing force of the pressing means, the urging means operates as the second cam mechanism. Since it acts in the direction of narrowing the interval, it is reliably released and no drag occurs, and as a result it is possible to contribute to improvement of fuel efficiency. In particular, claims 1, 2, 4,
In the case of 5, when the pair of members relatively rotating by the first cam mechanism are engaged with a force corresponding to the rotational torque, no force for reducing the engaging force acts at all. According to the sixth aspect, it is possible to reduce the hydraulic pressure applied to cause the pair of relatively rotating members to engage with each other with a force corresponding to the rotational torque.

[Brief description of the drawings]

FIG. 1 is a view schematically showing the structure of an automatic transmission according to the related art.

FIG. 2 is a diagram showing a combination of operations of each friction engagement element for obtaining each speed stage in the automatic transmission of FIG.

FIG. 3 is a diagram showing the overall structure of the first embodiment.

FIG. 4 is a view showing a structure of a cam portion of the first embodiment.

FIG. 5 is a diagram illustrating the operation of the first embodiment.

FIG. 6 is a diagram illustrating the operation of the first embodiment.

FIG. 7 is a diagram illustrating the operation of the first embodiment.

FIG. 8 is a view showing a structure of a cam portion of the second embodiment.

FIG. 9 is a diagram showing the overall structure of the third embodiment.

FIG. 10 is a view showing a structure of a cam portion according to a third embodiment.

FIG. 11 is a diagram showing an overall structure of a fourth embodiment.

FIG. 12 is a view showing a structure of a cam portion according to a fourth embodiment.

FIG. 13 is a diagram showing an overall structure of a fifth embodiment.

FIG. 14 is a diagram showing an overall structure of a sixth embodiment.

FIG. 15 is a view taken along line II of FIG. 14;

FIG. 16 is a diagram illustrating the operation of the sixth embodiment.

FIG. 17 is a view taken along line II-II in FIG. 16;

FIG. 18 is a diagram illustrating the operation of the sixth embodiment.

FIG. 19 is a view taken along the line III-III of FIG. 18;

FIG. 20 is a diagram illustrating the operation of the sixth embodiment.

FIG. 21 is a view taken along the line IV-IV in FIG. 20;

FIG. 22 is a diagram illustrating the structure and operation of a return spring according to a seventh embodiment.

FIG. 23 is a diagram illustrating the structure and operation of a return spring according to a seventh embodiment.

FIG. 24 is a diagram illustrating the structure of a return spring according to an eighth embodiment.

FIG. 25 is a diagram illustrating the operation principle of the eighth embodiment.

FIG. 26 is a diagram illustrating the operation principle of the eighth embodiment.

FIG. 27 is a diagram illustrating the structure of a return spring according to a ninth embodiment.

FIG. 28 is a view for explaining the operation principle of the ninth embodiment.

[Explanation of symbols]

B ₃ ... third brake K ₂ ... rear planetary carrier 1 ... clutch device 2 ... first cam member 3 ... piston (first, second embodiment) 3a ... piston (Third Embodiment) 3b ... second cam member ( Third Embodiment 3c Piston (third, fourth and fifth embodiments) 3d Piston (sixth embodiment) 3e Piston (seventh embodiment) 3f Piston (eighth and ninth embodiments) 4 Second cam member 4a Third cam member 5 First cam roller 6 Second cam roller 7 Return spring 7a Return spring (sixth embodiment) 7b Return spring (seventh embodiment) 7c Return spring (Eighth and ninth embodiments) 8 ... Clutch disk 9 ... Separator plate 10 ... Shift valve 11 ... Check valve 12 ... Drain control valve 13 ... Orifice 14 ... Aki Emulator 15 ... Spring seat 16 ... Groove 17 ... Protrusion 18 ... Protrusion 19 ... Guide hole 20 ... Spring support plate 21 ... Spring mounting pin 22 ... Ball 23 ... Ball receiving 24 ... Spring mounting pin 100 ... Clutch casing 200 ... Housing 200a ... Oil Passage 300: Oil passage

Claims (6)

(57) [Claims] 1. A pair of members which are spaced apart from each other on a common axis and relatively rotate, and a first frictional engagement element and a second frictional engagement element which can be engaged with each other, and one of the pair of members A first frictional engagement element that is engaged with the first frictional engagement element and is restricted from moving in the axial direction toward the second frictional engagement element; and a first frictional engagement element that is engaged with the other of the pair of members and is disposed adjacent to the first frictional engagement element. A second frictional engagement element, wherein the first and second frictional engagement elements are frictionally engaged to engage a pair of relatively rotating members, a pair of members on a common axis line A cam mechanism comprising a first cam mechanism and a second cam mechanism disposed therebetween, wherein the first cam mechanism has cam surfaces facing each other, and the first and second cams are respectively movable in an axial direction. A back surface opposite to the cam surface and a back surface opposite to the cam surface facing one of the first members. A first cam member being,
A back surface opposite to the cam surface includes, directly or indirectly, a second cam member which is brought into contact with the second frictional engagement element, wherein the second cam mechanism has cam surfaces facing each other, and each has a shaft. First and second cam members movable in a direction, the first cam member having a rear surface opposite to the cam surface directly or indirectly abutting against one of the first members; and a side opposite to the cam surface. And a second cam member having a back surface opposed to the second frictional engagement element, and a second cam member of the first cam mechanism is pressed toward the opposite side of the first cam member. Accordingly, there is provided a pressing means for pressing the second cam member of the second cam mechanism toward the second frictional engagement element, and an urging means for applying an axial urging force to a part of the cam mechanism. The coefficient of friction between the element and the back surface of the cam member of the first cam mechanism engaged with it is μ When the inclination angle of the first cam mechanism with respect to the plane perpendicular to the axis of the cam surface is β, and the inclination angle of the second cam mechanism with respect to the plane perpendicular to the axis is α, the first cam mechanism has a cam surface. The inclination angle β of the second cam mechanism is such that tan β> μ, the second cam mechanism has a cam surface inclined to the opposite side to the inclination angle of the first cam surface, and the inclination angle α is tan α <μ. When the second cam member of the second cam mechanism is pressed against the second friction engagement element by the piston means while the other of the pair of members to which the coupling element is coupled is rotating,
The first cam mechanism does not operate, the back surface of the second cam member of the second cam mechanism frictionally engages with the second friction engagement element and is dragged by the second friction engagement element, and the second cam mechanism faces the second cam mechanism. The pair of cam members rotate relative to each other and are pressed in directions away from each other, and the second
The first cam member of the cam mechanism directly or indirectly abuts one of the pair of members, and the first friction engagement element, against which the second friction engagement element is pressed by the second cam member, is restricted from moving in the axial direction. The second frictional engagement element and the first frictional engagement element are frictionally engaged with a pressing force corresponding to the transmission torque, and after the frictional engagement, the other of the pair of members to which the second frictional engagement element is coupled When the rotation direction is reversed, the separation between the first cam member and the second cam member of the second cam mechanism is eliminated, and the second cam member of the first cam mechanism is directly or indirectly dragged by the other of the pair of members. The pair of cam members facing each other in the one cam mechanism rotate relative to each other and are pressed in directions away from each other.
The second frictional engagement element is pressed against the first frictional engagement element directly or indirectly by the back surface of the second cam member of the cam mechanism to form the second frictional engagement element.
The friction engagement element and the first friction engagement element are frictionally engaged with a force corresponding to the pressing force of the pressing means, and the urging means presses the second cam member of the first cam mechanism toward the first cam member. A clutch device for applying an urging force. 2. The pressing means for applying a pressing force for canceling the urging force of the urging means when the other of the pair of members is rotating so that the second cam mechanism operates. A clutch device according to claim 1. 3. The biasing force of the biasing means when the other of the pair of members is rotating so that the second cam mechanism operates, and the other of the pair of members rotates when the second cam mechanism operates. 2. The clutch device according to claim 1, wherein the urging force is smaller than the urging force of the urging means when the clutch is engaged. 4. The urging means includes a spring member and a support member disposed between the spring member and the first cam member of the second cam mechanism to support the spring member. 4. The clutch device according to claim 3, wherein the supporting member receives the spring force of the spring member so as not to apply the urging force when the other of the pair of members is rotating to operate. . 5. The urging means comprises a spring member whose posture is changed by the relative rotation of the cam member, and when the other of the pair of members is rotating so that the second cam mechanism operates.
The clutch device according to claim 3, wherein the spring member has a natural length so as not to apply an urging force. 6. The biasing means comprises a spring member whose posture is changed by the relative rotation of the cam member, and the biasing means contracts when the other of the pair of members is rotating so that the second cam mechanism operates. The amount is set to be smaller than the amount of contraction when the other of the pair of members is rotating so that the first cam mechanism operates, and the other of the pair of members is adjusted so that the second cam mechanism operates. The urging force of the urging means when rotating
4. The clutch device according to claim 3, wherein the urging force of the urging means when the other of the pair of members is rotating so that the first cam mechanism operates is smaller.